Liquid seal and flow gauge



March 6, 1945. SHQLL, JR 2,370,755

- LIQUID SEAL AND FLOW GAUGE Fild D80. 26, 1942 H FIG. I sil 1s E a l I I! I,

' INVENTOR. HAROLD A. SHOLL JR Patented Mar. 6, 1945 UNITED A I STATES PATENT i o'trr ca P1 LIQUID SEAL AND FLOW GAUGE I .Harold A. Sholl, Jr., Philadelphia, Pa., assignor to' i v The Brown Instrument Company, Philadelphia, J Pa., a corporation of Pennsylvania Application December 26, 1942, Serial No. 470,153

Claims. (Cl. ia-zir) The present invention relates to control systems and in particular is directed toa liquid seal and flow gauge that-may be.used in-connection with a gas analyzing apparatus In systems of the type contemplated herein, asample of the gas to be analyzed is drawn through suitable cleaning and drying devices to a gas analysis device. From the latter it is passed through a sealing chamber and exhausted to the, atmosphere or returned to the processfrom which it was extracted. The purpose of the sealing chamber is to prevent a backward fiow of air or gas through the analyzing apparatus as well as to prevent the entrance of moisture thereto. In systems of this type it is desirable to provide some type of flow gauge to indicate if there isa' flow of the gas to be analyzed therethrough, and the amount of this flow.

It is an object of the present invention to provide a device that will act as a combination liquid seal and fiow gauge whichis simple in construction and operation. It is a further object of :the invention to provide a liquid fiow seal in which the liquid cannot be forced back into the analyzing apparatus even though the-re is an abnormal reverse fiow of gas through the system.

The various features of novelty which characterize my invention are pointed out with pare =ticularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, however, its advantages and specific objects obtained with its use,

had to the accompanying reference should be drawing and descriptive matter in which I have illustrated and described a preferred embodiment of the invention.

In the drawing:

Fig.1. shows the component'parts of a gas analyzing system, and

Fig. 2 is a view of the liquid seal and flow gauge of my invention.

Referring first to Figure 1, there is shown at l'a section of a furnace, the atmosphere of which isto be analyzed to determine, for example, the carbon dioxide content of the hydrogen content thereof. To this end, a sampling tube 2 projects into the furnace through an opening that is pro vided in one of its walls, and gas is drawn through this tube to a gas analyzing cell 3 b means of an aspirator 4. On passing to the cell from the furnace the gas must be conditioned and for this purpose various accessories are provided in its path. As the gas passes from the tube 2 it is pipe 5 first through a condenser E condense most of the moisture, the

directed by a that serves to ofthe bail serves to force the jar glycerine, to a level above the upper edge extends between the abail 2-4 and a thumb screw 25. The

condensate carrying with it the large particles of dirt that may be entrained in the gas. The gas next passesztoa dryer 1- that'may be filled with calcium chloride or other moisture absorbing material. The brine from this dryer falls into a drip well 8 from whichitmay be removed from time to time. Between the dryer and the cell 3, there is provided a secondary filter 9 which takesout the remaining moisture and dirt in the-gas. After the gaspassesthroughthe test cell and before it reaches the aspirator 4 it goes through a liquid seal and a fiowgauge I0, located between the two, that serves to prevent the return of the gas through the cell and which serves to give an indication of the amount of gas flowing through the system. The present invention is concerned more particularly with the construction of this combination seal and gauge and with its use in a gas analyzing system of thetype herein disclosed. The analyzing cell is connected electrically by means of a suitable cable H with a recording '01 indicating mechanism l2 upon which a record of the analysis of the gas is made. The flow gauge ill consists of a frame l5 which has formed in it an inlet opening'that is connected by pipe l6tothe cell 3'and is provided withan outlet opening to which the pipe I1, that gauge 10 and the aspirator 4, is connected. The frame has suspended from it in a suitable manner a gas chamber l8 which may be made of some transparent material such .as glass or which may be made of metal. This chamber has an orifice l9 formed in'its lower end, and the orifice is surrounded by a retaining collar 20 that extends upwardly into the chamber. A manometer tube Zl-is formed as shown,

and is located in the lower. part of the chamber l8 with its lower end below the upper edge of theretaining collar 20. The gas chamber I8 and the parts carriedthereby are surrounded "by a glass jar 22 which forms a second chamber and is held in engagement with a rubber or other suitable gasket 23 on the frame l5 by portion the lower end or the manoma small and pass through the orifice l9 to bubble up through the liquid in the jar 22 to be exhausted. The liquid between the retaining collar 20 and the wall of the chamber forms a reservoir to supply the manometer tube 2|. As the gas bubbles through the orifice 19 a differential pressure will be created between the interior and the exterior or the chamber I8. This differential pressure,

which is high on the interior of the chambenwill 'force the liquid in the reservoir upwardly into the manometer tube 2| an amount proportional to the flow of gas through the system. The amount that the liquid rises in the manometer it is therefore an indication of the fiow of the :gas, and may be used as a guide in adjusting the aspirator to obtain the proper volume of gas flow and keep the flow constant, When the sys'. tem is not in operation, the liquid in the unit will rise above the lower end of the tube 21 and the orifice l9 and will therefore, prevent any backward circulation or the gas into the system and into the furnace. This serves two purposesin that it. will prevent contamination or the controlled atmosphere of the furnace and it will prevent the'entrance of atmospheric moisture in the test cell, Upon an occurrence of an abnormally large fiow of gas through the system, all of the liquid may be blown out of the retaining collar and it may be blown out of the manometer tube 2i, but upon termination of the .fiow and reoccurrence ofanormal flow the liquid will return to its normal level and cover the retaining collar 20 so that the reservoir formed between the retaining collar 20 and the wall of chamber [8- will again be filled thus covering the lower end oi the manometer .sothat the flow gauge will properly operate to indicate the flow of gas. Upon theoccurrence of abackward flow oigas through the system, as may sometimes take place when air abnormal condition occurs, the liquid will merely be blown out or the manometer sincethat has the smallest static head, but as there will not be sufiicient liquid inthe manometer to fill up the chamber l8, none ot the seal,-

ing, liquid can pass back through the cell. or into the. remainder of the system,

It, will be seen. from the .above that I have provided. a combination flow gauge and liquid seal that isefiicient in .operationiandz simple in its construction. This seal can. be used: to great advantagein any gas/analysis systemiof the type disclosed herein, or any other system imwhich: a small constant flow of gas is to be: maintained and in which it is desired to prevent a backward flowthrough the system; 1

While in. accordance withthei provisions of the statutes, Iv have illustrated and described the best form of my invention now known to me, it willbe apparent to those skilled in the: art that changes may be made in the: form. of the apparatus disclosed, without departing from the spirit of my invention asset forth in the appended claims, and that in some cases certain features of my invention may sometimes be used to advantage without a corresponding use of other features. Having now described my invention, what I claim as new and desire to secure by Letters Patent, is: i

1. A device of the class describedcomprising a first member forming a chamber, a second member surrounding said first member and forming with the latter a second chamber, said first member having an orifice formed in it to connect said chambers, a tube open at both ends extending through said first member and having one end in; "each of said chambers, a liquid in said chambers of a quantity sufiicient to close both said orifice and one end of said tube, and a duct leading to each chamber above said liquid.

2. A device of the class described comprising an upstanding container having an inlet passage at, its top and an orifice at its bottom, a I

member surrounding said container, means cooperating with said member to form a chamber surrounding said container, an exhaust passage extendingfrom said chamber, a liquid seal between; the interior of said container and said chamber, the arrangement being such that gas flowing into said container will pass through said orifice to said chamber and exhaust therefrom, the gas bubbling through the liquid seal, and means extending between the interior of. said container and said chamber to give an indication of the volume of flow between the two.

3. In a device of:the class described a pair of concentric members forming a pair of concentric chambers, the inner member being formed with an o enin'g therein to connect the two chambers, a co ar surrounding said op'eningand extending into the inner member to form a reservoir in said member, a tube open at both ends extendingv through the inner chamber so that one end is in each chamber, the end of the 'tube in the inner chamber terminating in said. reservoir, and

a duct leading to each chamber.

4. In a device of the class described, a container having a bottom and a side wall, said bottom wall having an opening therein, an upstanding collar surrounding said c nemas, and a tube having. an open upper and an open lower end, the said lower end extending through the .said inlet passage, said member being formed with an ope'ning in a lower wall thereot'and being provided with a portion to forma-small'reservoir therein, a manometer tube having one end extending. into said reservoir, a casing extending around the. outside of said member and tube and engaging said frame with apressure: tightconnectiom, and aliqu-idin said casing, to a l'evelito fill said reservoir formed in said member;

HAROLD A. JR; 

